1. Field of the Invention
The present invention relates to a power inductor having excellent inductance characteristics and improved reliability, and a method of manufacturing the same.
2. Description of the Related Art
Examples of electronic components using a ceramic material include a capacitor, an inductor, a piezoelectric element, a varistor, a thermistor, and the like.
Among these ceramic electronic components, an inductor, an important passive element configuring an electronic circuit, together with a resistor and a capacitor, may mainly be used as a component for removing noise or configuring an LC resonance circuit.
An inductor may be manufactured by winding coils around a ferrite core or printing a coil pattern on the ferrite core and forming electrodes at both ends thereof, or may be manufactured by printing internal electrodes on a magnetic material or a dielectric material and then stacking layers of the magnetic material or the dielectric material.
An inductor may be divided into one of several types thereof, such as a multilayered type inductor, a winding type inductor, a thin film type inductor, and the like, according to a structure thereof. Manufacturing methods of the respective inductors, in addition to ranges of application thereof, differ.
Among the types of inductors, the winding type inductor may be formed by winding coils around, for example, a ferrite core. However, in a case in which the number of windings is increased in order to obtain high inductance, stray capacitance between coils, that is, capacitance between conducting wires may be generated, such that high frequency characteristics are deteriorated.
In addition, a power inductor may be manufactured as a laminated body in which ceramic sheets formed of a plurality of ferrite or low-k dielectric materials are stacked.
Here, the ceramic sheets may have coil type metal patterns formed thereon. The coil type metal patterns formed on the respective ceramic sheets may be sequentially connected to each other by conductive vias formed in the respective ceramic sheets, and may form an overlapping structure in a vertical direction in which the ceramic sheets are stacked.
According to the related art, an inductor body configuring the power inductor has generally been formed of a quaternary ferrite material including nickel (Ni), zinc (Zn), copper (Cu) and iron (Fe).
However, this ferrite material has a saturation magnetization value lower than that of metal, such that high current characteristics required in a recent electronic product may not be able to be implemented therein.
Meanwhile, in the case in which the inductor body of the power inductor is formed of a metal component, the saturation magnetization value may be relatively increased as compared to the case in which the inductor body is formed of ferrite. However, in this case, eddy current loss and hysteresis loss may be increased at a high frequency, such that material loss may be intensified.
In order to reduce material loss, according to the related art, a structure in which metal powder particles are insulated from each other with a polymer resin has been used. However, in this case, a volume fraction of metal may be decreased when the content of the polymer resin is increased, such that an effect of increasing a saturation magnetization value by the use of the metal component, may not be sufficiently implemented.
Meanwhile, in the case in which the volume fraction of metal is increased, the content of the polymer resin is decreased. In this case, a high level of acidic or basic solution used in the manufacturing of an inductor permeates into a chip, which may cause a reduction in inductance characteristics.